IF you find it difficult to tell Murray cod and trout cod apart, you’re not alone! But, according to the Victorian Fisheries Authority, it’s really important to learn to tell the difference.
Murray cod Maccullochella peelii and trout cod Maccullochella macquariensis look very similar, have an overlapping distribution, and both love instream woody habitats. However, while Murray cod are found across much of the Murray-Darling Basin, trout cod only occur in a far more restricted area. Trout cod have declined dramatically; by the late 1980s only a single naturally occurring population was known, in the Murray River between Yarrawonga to Cobram. Encouragingly, trout cod have since been successfully reintroduced into other areas and are slowly showing some recovery.
Both fish species are considered threatened and sustainability of their populations is at risk, and while Murray cod are a prized catch with anglers, trout cod are protected. There has long been a belief that some trout cod may be accidentally kept by anglers, thinking they were Murray cod…but we didn’t know how significant this misidentification issue might be. To find out, scientists from the Arthur Rylah Institute, DELWP, analysed almost 20 years of records from a fish mark and recapture program in the Murray River between Yarrawonga and Tocumwal to determine rates of misidentification by anglers.
Results showed that up to 40% of trout cod captured were misidentified; and the larger the trout cod, the more likely it would be misidentified. The unintended take of trout cod by anglers can affect the species chances of recovery. In addition, the increasing human population in south east Australia and increased use of waterways by anglers will increase the probability of capture of trout cod. It is important that fisheries managers understand the significance of current threats to this species, including accidental take. Concerted efforts by a range of agencies have addressed a range of threats to trout cod, through restoring habitat, stocking fish, monitoring populations and educating anglers, and these efforts have supported encouraging signs of recovery of trout cod in recent years.
A recent paper by Lyon et al. (2018) stressed the need for fisheries and conservation managers and anglers to work together on solutions to the issue of misidentification and accidental take of trout cod. A multi-pronged approach is needed, including ongoing commitment to enforcement of fishing regulations, continued collaboration between government and anglers and advocacy groups, and education campaigns. Social media platforms can provide a valuable tool to build awareness of the importance of identifying trout cod correctly, including with urban audiences.
Click HERE for information on the identifying features of Murray cod and trout cod.